I have a Raspberry Pi 3B+ running Raspbian 32 bit. It runs correctly as an access point and a wifi client over the integrated wifi. It does not use systemd-kerneld. I followed the different steps mentioned and froze the wifi firmware version as suggested in the first post to firmware-brcm80211_20190114-1+rpt4_all.deb. All works fine for a few hours and at some point, the pi loses wlan0 : the network indicator states that wlan0 is disassociated from my internet box. When typing dmesg I have the following error repeating :
[20295.746407] ieee80211 phy0: brcmf_run_escan: error (-52)
[20295.746432] ieee80211 phy0: brcmf_cfg80211_scan: scan error (-52)
Does anyone have an idea of what might be causing this error when nothing specific seems to occur to create this error ? Is there some logs I could look at to understand better the issue ?